1. Field
Embodiments relate to a display device capable of improving visibility and a method for controlling the same.
2. Description of the Related Art
Display devices display visual and stereoscopic image information.
Currently, flat display devices having low restrictions in installation space due to their small weights and sizes compared to cathode ray tubes, capable of implementing a large screen and a flat panel, and having excellent performance, for example, high image quality, have been developed.
Representative examples of the flat display devices include a liquid crystal display (LCD), an electro-luminescent display (ELD), an organic light emitting diode (OLED), a field emission display (FED), a plasma display panel (PDP), a thin film transistor (TFT)-LCD, and a flexible display.
The display devices may be categorized into transmissive display devices and reflective display devices.
A transmissive display device may include, for example, a backlight unit having a light source therein and thus externally emit light generated by the light source. A representative example of the transmissive display device is an LCD.
The LCD has a high response speed to display a video image, has a low afterimage effect, and is capable of displaying various colors. However, the LCD has a short battery life depending on display brightness and has a dark visibility in an outdoor environment compared to sunlight.
Specifically, a portable device used anywhere without restriction of location is mostly used in an environment having bright external light, e.g., sunlight. However, the visibility of a display device is greatly reduced.
To prevent a reduction in visibility of a display device under bright external light, the luminance of the display device should be increased. However, power consumption of a portable device is increased. Since the portable device requires low power consumption to remain portable, the above technology may not be easily used.
Furthermore, a transmissive display device such as an LCD or an OLED has structural restrictions in that a light source should always be driven to display an image, and thus may not easily achieve minimized power consumption and excellent visibility in an outdoor environment at the same time.
A reflective display device displays certain information by reflecting external light. The reflective display device is capable of displaying a clear and bright image by reflecting bright light such as sunlight in an outdoor environment, but has a low refresh rate, has an afterimage effect, has low visibility in low light conditions, and is not capable of displaying various colors.